PNSO Ligands as a Tool to Study Metal Bonding of Electron-Deficient Sulfinyl Groups

A family of :N-phosphanylsullinamide (PNSO) ligands with electron-deficient sulfinyl groups was synthesized. Reaction with Co-2-alkyne complexes yields PS-bridged complexes. These complexes were used to study the metal bonding of different sulfinyl groups IR spectroscopy, X-ray analysis, and Pauson-Khand reactivity studies indicated that electron-deficient sulfinyl groups provide enhanced S metal bonding The mean CO stretching frequencies (Av) for these complexes closely correlates with the Zi parameter computed by Tolman for phosphane ligands Among the studied sulfinyl groups, the trifluoromethyl PNSO ligand afforded the strongest sulfur-metal bond. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)